Sir i had unprotected vaginal sex on jun14th with a commercial sex worker whose status is unknown for HIV.My intercourse duration will be less than or equal to one minute & moreover i did not ejaculate inside her.when i about to orgasm my penis is outside and am ejaculating.what are my chances of getting infection? I took P24 antigen test on July2nd that is 18th day after my potential exposure and the result came negative.whether there are chances of false negative?? Pls help me am too afraid!!